Daniel Kahneman gave a fascinating talk about two kinds of happiness: the happiness you experience in the moment, and the happiness you feel when remembering an event later.

This idea got inside my head and wouldn’t go away. Basically, studies have shown that people will report very different levels of pain or pleasure while they are having an experience, compared to what they report looking back on it later. I take this to mean that not only is happiness subjective (per person), but it is also a function of time. Or, another way to see it is to realize that the person you are changes over time. We may know this already, but it is inconvenient and disorienting and at odds with the illusion of a constant self, so we tend to forget it and move on with our lives.

Kahneman captured the difference in this thought experiment:

Imagine that for your next vacation, you know that at the end of the vacation all your pictures will be destroyed, and you’ll get an amnesic drug so that you won’t remember anything. Now, would you choose the same vacation?

Another observation he shared is that one’s later reflection on an experience is most influenced by how it ended. A positive or pleasant ending colors the entire experience, and the same is true if the end is painful or unpleasant. Remembered happiness is clearly *not* the integral of momentary happiness.

But if this is true, what does it mean for people who seek happiness? Which kind of happiness is the one you want to optimize? If you optimize happiness in the moment, arguably you are happier for more of the total time. But you might not *feel* that way, looking back later. If there were unpleasant bits near the end of an experience, they could dwarf all of the intermediate pleasure. But if you optimize retrospective happiness, this could come at the cost of a lot of momentary pain and unhappiness (which you later forget). Which self do you care more about? Since the remembering self is the one who lives on (the momentary self is arguably dead after the moment passes), maybe that self should win. What’s a person to do?

Kahneman did not answer this question. He also didn’t address the fact that the remembering self, each time it remembers, updates and reinforces and alters the memories slightly, so ultimately happiness is a fluid quantity that won’t sit still even if you were to stop having new experiences.

It’s possible that Kahneman has gotten me to way over-think this question. And yet I can’t quite let it go. The pursuit of happiness and a good life is the fundamental question of philosophy and living. With this idea, Kahneman has also pointed out that it is also inextricably tied to identity. Which self is *me*? Both. But I can only live one life. Hmmm!